Trypsin Inhibitor Content Research Articles

The impact of soaking and drying soybeans on soyflour and the gluten-free cookies made from it

This study investigated the effects of drying and soaking conditions on soy flour, as well as their influence on cookie quality. Two drying methods (70°C for 10 hours and 90°C for 6 hours) and three soaking conditions (ambient temperature for 24 hours, 80°C for 2 hours, and 121°C for 10 minutes) were evaluated. High-temperature soaking and drying resulted in darker flour with lower L* values (81.06–89.44) and higher a* values (-0.36–5.25) (p < 0.05). Scanning electron microscopy showed that the treated flour had rougher surfaces and protein clustering, which made it less foamy, and less emulsifying but better at water absorbing and holding. With heat treatment, the trypsin inhibitor content decreased significantly from 50.21 mg/g to 33.01 mg/g (p < 0.05). Gluten-free cookies made from soy flour treated at 80°C for 2 hours soaking and 90°C for 6 hours drying showed comparable spread ratios to wheat cookies and lower hardness. This treatment also allowed for higher protein (24.92%) and fiber (22.29%) content in the cookies. Therefore, soaking soybeans at 80°C for 2 hours, followed by drying them at 90°C for 6 hours, is recommended to produce soy flour suitable for developing high-protein, high-fiber, gluten-free cookies.

Nutritional attributes and microbial metagenomic profile during solid-state fermentation of soybean meal inoculated with Lactobacillus acidophilus under non-sterile conditions.

Soybean meal (SBM) is used widely in animal feed but it contains anti-nutritional factors (ANFs) such as protease inhibitors - immunogenic proteins that limit its utilization. Fermentative processes could help to reduce these ANFs. The aim of this study was to evaluate the nutritional attributes, bacterial community dynamics, and microbial metagenomic profile during the solid-state fermentation of SBM using a strain of the bacterium Lactobacillus acidophilus with or without pre-autoclaving treatment. Following fermentation, there was a reduction in the pH and a concurrent increase in the population of lactic acid bacteria. Fermentation also resulted in an increase in both crude and soluble protein levels. Trypsin inhibitor levels decreased after fermentation, particularly in fermented SBM that had not been pre-autoclaved, with an inactivation rate higher than 90%. Moreover, high-molecular-weight peptides (44-158 kDa), specifically some polypeptides from the soybean immunogen glycinin and β-conglycinin, underwent degradation during the fermentation process. Bacterial community analysis revealed the dominance of the Lactobacillus genus in all samples, regardless of the treatments applied. Metagenomic profiling identified L. acidophilus as the dominant species in inoculated SBM, irrespective of whether pre-autoclaving was conducted or not. This study demonstrates the feasibility of solid-state fermentation with L. acidophilus under non-sterile conditions to inactivate trypsin inhibitor and increase protein concentration and hydrolysate immunogen proteins into low-molecular-weight peptides in SBM. Lactobacillus acidophilus inoculum also inhibited the growth of undesirable bacteria. This knowledge contributes to our understanding of the potential applications of solid-state fermentation with L. acidophilus in improving the nutritional quality of SBM. © 2024 Society of Chemical Industry.

137 Impact of dietary soybean-mediated trypsin inhibitor concentrations on nursery pig performance

Abstract Antinutritional factors associated with soybeans and soy products, such as trypsin inhibitor proteins, have been shown to hinder amino acid bioavailability and, consequently, affect the growth performance of pigs. Thus, our objective was to assess the impact of dietary trypsin inhibitor units (TIU; expressed as TIU/mg of feed) on nursery pig performance and health. Sixty barrows [5.56 ± 0.65 kg body weight (BW), Camborough (1050) x 337, (PIC, Hendersonville, TN)], freshly weaned and 19 to 21 d of age were randomly selected and allotted across six dietary treatments (10 pigs/treatment) in a randomized complete block design. All pigs were individually penned with ad libitum access to water and feed. Diets were administered in two phases directly post-weaning, spanning 14 and 28 d, respectively, and the entire test period extended for 42 d. Within each phase, diets were formulated to be isocaloric, with uniform NDF and SID lysine concentrations. In both phases, TIU were incrementally adjusted by the inclusion of soybean meal, raw ground soybeans, soybean oil, and soyhulls to attain a target TIU/mg feed of 0.5, 1, 2, 3, 4, and 6. All diets were analyzed for active TIU/mg. Pig BW and feed disappearance were measured at the start and end of each phase to compute average daily gain (ADG), average daily feed intake (ADFI), and gain to feed ratio (G:F). Fecal consistency was assessed daily in phase 1. Pig was the experimental unit and data were analyzed with the effect of diet, including the linear and quadratic contrasts, evaluating dietary TIU levels. The average analyzed TIU/mg over both diet phases were 0.38, 0.54, 1.85, 3.16, 3.90, and 5.79 TIU/mg diet, respectively. Fecal consistency scores did not differ across diets. At the end of phase 1, BW decreased from 8.7 to 6.9 kg as TIU/mg diet increased from 0.38 to 5.79 (linear P < 0.05). Similarly, by d 42, BW decreased from 25.3 to 15.5 kg with the increase in dietary TIU/mg from 0.38 to 5.79 (linear P < 0.0001). Both phase 1 and 2 showed a decrease in average daily gain (ADG) and G:F as TIU increased (linear P < 0.05). ADFI exhibited a decreasing trend in phase 1 (linear P = 0.079) and a decrease in phase 2 (linear P < 0.05) as dietary TIU increased. No quadratic responses were reported for ADG and G:F. Overall, as TIU increased, ADG, ADFI, and G:F were reduced, with 5.79 TIU/mg feed resulting in a decrease of these parameters by 8 to 22% (linear P < 0.01). In conclusion, increasing TIU levels in the diet had detrimental effects on nursery pig performance. The most significant negative impacts on growth, feed intake, and feed efficiency were observed in diets containing 3.16 to 5.79 TIU/mg feed.

Impact of non‐thermal processing on the nutritional quality and bioactive properties of industrial hempseed flours and protein isolate

AbstractThere is an unmet demand for plant‐based ingredients with desirable nutritional, techno‐functional properties, and health benefits. In this study, the composition, nutritional quality, and bioactives in industrial hempseed flours and protein isolate generated by milling, germination, isoelectric precipitation (IEP), and enzyme‐assisted extraction (EAE) were evaluated. Moisture, ash, fat, protein, phytic acid, tannin, and trypsin inhibitor content of the hempseed flours and protein isolate were 2.80%–6.46%, 5.07%–28.89%, 0.00%–31.44%, 22.71%–89.94%, 0.55%–1.05%, 274.24–1300.76 μg/g, and 0.00–42.66 U/g, respectively. IEP resulted in the highest protein content (89.94%), indicative of its effective to isolate hempseed protein. Germination and IEP significantly reduced phytic acid and tannin contents by 1.53‐ and 3.63‐fold, respectively. All processing methods improved in vitro protein digestibility (IVPD). SDS‐PAGE analysis revealed comparable band patterns in milled and protein isolate, with a strong 50 kDa band attributed as edestin. Amino acid analysis showed that EAE augmented total essential amino acids, particularly protease. Milling and pronase treatment yielded the highest and lowest IVPD‐corrected amino acid score (IVPDCAAS) of 76% and 47%, respectively. Milled and germinated flours contained varying amounts of γ‐tocopherol, lutein, zeaxanthin, α‐carotene, and β‐carotene. Germinated flour exhibited elevated levels of total phenolic (14.36 mg/g), and flavonoid (1.76 mg/g) contents, FRAP, TEAC, and DPPH compared to the other flours suggesting superior antioxidant capacity. Strong positive correlations (r >0.70) were found between IVPD and phytic acid for the protein isolate, total phenolic content, and FRAP for IEP and germinated flours. Overall, hempseed flours with diverse properties could be produced using non‐thermal processing.

Fermented soybean meal improved laying performance and egg quality of laying hens by modulating cecal microbiota, nutrient digestibility, intestinal health, antioxidant and immunological functions

Antinutritional factors in feedstuffs may limit their utilization in livestock production, but fermentation process can be used to improve feed quality; however, studies on fermented soybeans for laying hens remain limited. We investigated the effect of fermented soybean meal (FSBM) at various inclusion levels as a partial replacement for soybean meal (SBM) on egg production, egg quality, amino acid digestibility, gut morphology and microbiota, antioxidant capacity and immune response of young laying hens. A total of 360 Hy-line Brown laying hens aged 18 weeks were selected and divided into 5 groups of 6 replicates each and 12 birds per replicate. The control group received a basal diet while the trial group received the basal diet with FSBM included at 2.5%, 5.0%, 7.5% and 10.0%, respectively, for 12 weeks. Our findings revealed that the nutritional value of FSBM was higher compared to that of SBM in terms of reduced content of trypsin inhibitors and increased contents of crude protein, amino acids and minerals. FSBM enhanced egg production (P < 0.05), feed-to-egg ratio (P < 0.05), and albumen quality (albumen height and Haugh unit) (P < 0.05). Furthermore, FSBM improved apparent fecal amino acid digestibility (P < 0.05), gut morphology (increased villus height, villus width, villus height-to-crypt depth ratio and decreased crypt depth) (P < 0.05), antioxidant capacity (reduced malondialdehyde and increased catalase, total superoxide dismutase, glutathione peroxidase and total antioxidant capacity) (P < 0.05) and immune function (increased concentrations of IgG, IgA, and IgM; increased levels of transforming growth factor beta and Toll-like receptor 2; and reduced levels of interleukin 1β and tumor necrosis factor alpha) (P < 0.05). Further analysis showed that FSBM altered the composition of the gut microbiota favoring beneficial microbes. These findings suggest that probiotic fermentation improved the nutritional value of SBM. The inclusion of FSBM in the diets of laying hens at 2.5% or 5.0% improved amino acid digestibility, gut health, immune function, egg production and egg quality.

REVIEW OF MODERN TECHNOLOGIES FOR INACTIVATION OF ANTI-NUTRIENTS IN SOYBEANS

The study examines technologies for inactivating anti-nutrients in soybeans, such as proteolytic enzyme inhibitors. In addition, soybeans have two trypsin inhibitors that bind cystine and methionine. Protease inhibitors include trypsin and chymotrypsin inhibitors, which are substances that are naturally present in soybeans to protect them from being eaten by birds and rodents and from the development of microflora. According to their heat resistance, antinutrients can be classified into heat-sensitive and heat-resistant. The purpose of the research was to study modern methods and technological solutions aimed at optimizing the preservation of useful characteristics of soybeans and reducing the content of anti-nutrients. To inactivate these anti-nutrients, physical, chemical and biological methods of legume processing are used. As a result of heat treatment, the nutritional value of beans increases, namely, the digestibility of proteins increases by up to 90%, and the contamination of beans with microflora is significantly reduced. The amount of trypsin inhibitor in soybeans after roasting with a roaster significantly decreased by 2.45 times, and lipoxygenase activity - by 2.71 times. One of the most attractive and highly effective, but not sufficiently researched methods is the method of heat treatment of legume seeds called micronization. In this case, the process of inactivation of anti-nutrients in soybeans is very fast - within 50...70 seconds, the nutritional value of protein is significantly increased, and the energy value increases (approximately from 7800 to 16000 kJ/kg). The technology of neutralization of anti-nutrients in soybeans based on their heat treatment in a 2.5 % solution of calcium hydroxide is considered. Processing of soybeans according to the developed technology allows to obtain feed without urease activity, and the content of trypsin inhibitor is at the level of 2-3 mg/g.

Effect of different strains on quality characteristics of soy yogurt: Physicochemical, nutritional, safety features, sensory, and formation mechanism

The purpose of the study was to explore effect of four different strains on quality characteristics of soy yogurt. The results showed that four strains were all related to the genus Lactobacillus and N1 was Lacticaseibacillus rhamnosus, N2 was Lacticaseibacillus paracasei, N3 was Lacticaseibacillus plantarum, and N4 was Lacticaseibacillus acidophilus. The result analysis of biochemical, sensory, nutritional, functional and safety properties of fermentation process and end products showed that the soy yogurt fermented with L. rhamnosus N1 had the highest isoflavone content and the lowest phytic acid content; the soy yogurt fermented with L. paracasei N2 had the highest content of free amino acids and oligosaccharides, the lowest content of trypsin inhibitors; the soy yogurt fermented with L. plantarum N3 had the lowest oil content; the soy yogurt fermented with L. acidophilus N4 had optimal functional properties. In summary, N4 was suitable as a fermentation strain for soymilk.

Estimation of lesser known anti-nutrients; Phytic acid and Trypsin inhibitor from the edible bamboo shoots and their processed products of Arunachal Pradesh, India

Bamboo shoot is well known for the high nutritive values it possesses. People in Northeastern India, the majority of which are tribal and lives in rural area consume bamboo shoot extensively without knowing its benefits and demerits. The present study was undertaken in Arunachal Pradesh, India considering the possible threats it may pose to the people of the region in particular by estimating the anti-nutritional elements such as Phytic acid and Trypsin inhibitor from bamboo shoots of seven species and its three processed forms that are widely consume. Phytic acid content was observed within a range of 0.81 to 0.31 Pmg/100g and 0.75 to 0.38 Pmg/100g in bamboo shoots and processed products respectively whereas trypsin inhibitor in tender shoots of all the seven species (0.53-0.24 TIU mg/protein) and processed products (0.37-0.19 TIU mg/protein) was also recorded. Similarly, there were also significant variations in phytic acid (F=41.509, P&lt;0.001) and trypsin inhibitor (F=16.631, P&lt; 0.001) concentration between the fresh shoots and processed forms. The amount of antinutrients estimated from these samples are considerably less and far from any harm.

Assessment of soy genotype and processing method on trypsin inhibitors, urease and lectins content of tofu

Tofu has a high nutritional value, but it may also contain components that may have an antinutritional effect, such as trypsin inhibitors (TI), lectins and ureases. The aim of this study was to investigate the influence of the hydrothermal-cooking process of soybean in combination with commercial chymosin-pepsin rennet on the content and activity of TI, urease and lectins in tofu. High total TI content was found in tofu (5.00-16.87%). In addition, Kunitz (KTI = 3.52-4.32%) and Bowman-Birk (BBI = 5.00-12.53%) TI were registered, and BBI was detected in polymeric (1.38-2.71%) and monomeric (3.42-9.82%) forms. TI activity of tofu was very low (5.86-9.34%), corresponding to the very low activity of urease (0.51-3.07%). The percentage of lectin (2.62-4.63%) and urease (0.03-0.12%) in tofu was low. The results showed that the applied tofu production process is very effective in reducing the content and activity of TI, urease and lectin and provides the values without nutritional harmful effect.

Study on the antioxidant activity of peptides from soybean meal by fermentation based on the chemical method and AAPH-induced oxidative stress.

Preparation and antioxidant activities of soybean peptides using solid fermentation to decrease the content of trypsin inhibitor (TI) and antigen protein were investigated in this study. The results showed the optimal fermentation conditions were as follows: fermentation time 48 h, the ratio of material to solvent 1:2, inoculum size 12%, and the ratio of Lactic acid bacteria and Aspergillus oryzae 2:1. The hydrolysate was were divided into four components of <1, 1-3, 3-5, and >5 kDa by ultrafiltration based on molecular weight, and the <1 kDa peptides expressed the highest antioxidant activities. Meanwhile, the cell antioxidant activity of the <1 kDa soybean peptides was investigated using AAPH-induced erythrocyte hemolysis, which effectively inhibited erythrocyte hemolysis with the inhibit rate of 85.8% through inhibition of the ROS intracellular generation. In addition, soybean peptides could significantly restore the intracellular antioxidant enzymes (SOD, GSH-Px, and CAT) activities, as well as inhibited intracellular MDA generation and depletion of GSH. The intracellular antioxidant detoxifying mechanism of soybean peptides was associated with both non-enzymatic and enzymatic defense systems. According to this study, fermentation could effectively improve the antioxidant activities of soybean peptides.

The growth and probiotic characteristics of Bacillus velezensis BS in soybean meal used as synbiotic-like preparations for Litopenaeus vannamei culture

Soybean meal (SBM) is the by-product of soybean oil extraction. It is well known to contain at least 47% protein and more than 6% crude fiber. This study showed that Bacillus velezensis BS grew well in medium containing 1% SBM and gained the prebiotic index and activity score of 15.40 ± 4.10 and 0.85 ± 0.22, respectively. In this medium, B. velezensis BS showed various probiotic characteristics, such as digestive enzyme secretion (α-amylase, cellulase, and protease), anti-Vibrio parahaemolyticus, biofilm formation on the solid surface after 24 h of interaction and the ability to grow in a broad range of environmental conditions (pH 6-9, temperature of 20-45ºC, salinity of 4%). In addition, SBM fermented with B. velezensis BS significantly reduced 79.7 ± 1.9% of the trypsin inhibitor content. Dietary supplement of the fermented product in Litopenaeus vannamei culture improved the specific growth rate of shrimp by approximately 7 times and concomitantly decreased the density of V. parahaemolitycus pathogen by 10 times compared to the group without synbiotic-like fed. Hence, the B. velezensis BS and its SBM fermented product were suggested as a potential feed additive in aquaculture applications.

Assessing the Nutritional and Antinutritional Components of Promising Kabuli Chickpea (Cicer arietinum L.) Genotypes

The present investigation on “Assessing the Nutritional and antinutritional componants of promising kabuli chickpea (Cicer arietinum L.) genotypes” was carried out with an objective to analyze different 20 promising genotypes of kabuli chickpea for various nutritional and anti-nutritional components. The highest protein content (25.37%) and phytic acid (12.29 mg g-1) were recorded in kabuli chickpea genotype GJGK-1828. The highest value of total sugar content was observed in ICCV-191310 (4.73%) and maximum ash content was found in ICCV-191302 (3.47%). The minimum phytic acid was recorded in genotype ICCV-191301(10.43 mg g-1) which found distant genotypes in dendrogram prepared using biochemical data. The higher trypsin inhibitor was recorded in kabuli chickpea genotype GJGK-1826 (10.33TIU/mg) and lowest trypsin inhibitor content noticed in genotype ICCV-191302 (14.33TIU/mg) and both were fall in different cluster of dendrogram. Minimum value of total phenol was found in ICCV-181314(87.87 mg 100 g-1) and maximum value was observed in kabuli chickpea genotype GKGK-1826 (93.98 mg 100 g-1). Thus, the wide variability of nutritional and antinutritional parameters was observed among the genotype studied.

Development of new mutant alleles and markers for KTI1 and KTI3 via CRISPR/Cas9-mediated mutagenesis to reduce trypsin inhibitor content and activity in soybean seeds.

The digestibility of soybean meal can be severely impacted by trypsin inhibitor (TI), one of the most abundant anti-nutritional factors present in soybean seeds. TI can restrain the function of trypsin, a critical enzyme that breaks down proteins in the digestive tract. Soybean accessions with low TI content have been identified. However, it is challenging to breed the low TI trait into elite cultivars due to a lack of molecular markers associated with low TI traits. We identified Kunitz trypsin inhibitor 1 (KTI1, Gm01g095000) and KTI3 (Gm08g341500) as two seed-specific TI genes. Mutant kti1 and kti3 alleles carrying small deletions or insertions within the gene open reading frames were created in the soybean cultivar Glycine max cv. Williams 82 (WM82) using the CRISPR/Cas9-mediated genome editing approach. The KTI content and TI activity both remarkably reduced in kti1/3 mutants compared to the WM82 seeds. There was no significant difference in terms of plant growth or maturity days of kti1/3 transgenic and WM82 plants in greenhouse condition. We further identified a T1 line, #5-26, that carried double homozygous kti1/3 mutant alleles, but not the Cas9 transgene. Based on the sequences of kti1/3 mutant alleles in #5-26, we developed markers to co-select for these mutant alleles by using a gel-electrophoresis-free method. The kti1/3 mutant soybean line and associated selection markers will assist in accelerating the introduction of low TI trait into elite soybean cultivars in the future.

Double-Fermented Soybean Meal Totally Replaces Soybean Meal in Broiler Rations with Favorable Impact on Performance, Digestibility, Amino Acids Transporters and Meat Nutritional Value

Inclusion of microbial fermented soybean meal in broiler feed has induced advantageous outcomes for their performance and gastrointestinal health via exhibiting probiotic effects. In this study, soybean meal (SBM) was subjected to double-stage microbial fermentation utilizing functional metabolites of fungi and bacteria. In broiler diet, DFSBM replaced SBM by 0, 25, 50 and 100%. DFSBM was reported to have higher protein content and total essential, nonessential and free amino acids (increased by 3.67%, 12.81%, 10.10% and 5.88-fold, respectively, compared to SBM). Notably, phytase activity and lactic acid bacteria increased, while fiber, lipid and trypsin inhibitor contents were decreased by 14.05%, 38.24% and 72.80%, respectively, in a diet containing 100% DFSBM, compared to SBM. Improved growth performance and apparent nutrient digestibility, including phosphorus and calcium, and pancreatic digestive enzyme activities were observed in groups fed higher DFSBM levels. In addition, higher inclusion levels of DFSBM increased blood immune response (IgG, IgM, nitric oxide and lysozyme levels) and liver antioxidant status. Jejunal amino acids- and peptide transporter-encoding genes (LAT1, CAT-1, CAT-2, PepT-1 and PepT-2) were upregulated with increasing levels of DFSBM in the ration. Breast muscle crude protein, calcium and phosphorus retention were increased, especially at higher inclusion levels of DFSBM. Coliform bacteria load was significantly reduced, while lactic acid bacteria count in broiler intestines was increased with higher dietary levels of DFSBM. In conclusion, replacement of SBM with DFSBM positively impacted broiler chicken feed utilization and boosted chickens' amino acid transportation, in addition to improving the nutritional value of their breast meat.

Composition of proteins in fresh whey as waste in tofu processing

Tofu whey is a pale-yellowish liquid with specific aroma/taste which remains as the byproduct/waste after tofu squeezing and represents an environmental problem for direct disposal. Understanding the fresh tofu whey protein composition and the activity of bioactive peptides could be useful for the application of tofu whey as a functional food additive. Tofu whey was obtained during the tofu production from six soybean genotypes by hydrothermal processing in combination with chymosin-pepsin rennet. Basic 7S globulin (14.28–19.13%), γ-conglycinin (7.73–9.31%) and β-conglycinin (10.59–12.90%) were registered of the total extracted proteins. Glycinin was present with a dominant share of acidic (24.64–27.55%) versus basic polypeptides (12.18–14.61%) in the total extracted proteins. High content of total protein (22.67–28.00%), balanced content (9.76–13.33% of the total extracted proteins) and residual activity (1.95–3.76%) of trypsin inhibitors and low lectins content (5.04–5.48% of the total extracted proteins) indicate good nutritional value of the tofu whey samples. Tofu whey can be potentially useful for application as a cheap, nutritional and functional food additive and can enable sustainable production through the recycling of waste.

Nutritional and Functional Properties of Wheat-Defatted Peanut-Orange Peel Composite Flour

The need to improve and enhance the nutritional quality of locally made foods (bakery and confectionaries) cannot be overemphasized. This study set out to meet this need by producing composite flours from wheat, defatted peanut and orange peel flour blends which will serve an even greater issue of reducing the cost of wheat importation and use. The samples were coded as follows: A-100:0:0, B-90:5:5, C-85:10:5, D-80:15:5, E-75:20:5 of wheat flour: Defatted peanut flour: orange peel flour. The flours produced were analyzed for functional, anti-nutrient, proximate, minerals, and phytochemical properties. The functional properties of flours; bulk density, swelling capacity, OAC, WAC, and Foaming capacity ranged from 0.43 to 0.93 g/ml, 0.89 to 5.67%, 0.47 to 2.55 g/L, 1.75 to 4.35ml/g, 0.52 to 10.56% respectively. The anti-nutritional properties: phytates, tannins, and trypsin inhibitor content of flours ranged from 0.0352 to 0.0845%, 0.040 to 0.600%, and 0.011 to 0.048mg/g respectively. The proximate composition of the flour samples, Moisture, Protein, fats, crude fibre, ash, carbohydrates, and energy values ranged from 5.58 to 9.55%, 6.33 to 15.64%, 1.06 to 3.51%, 0.24 to 4.07%, 1.42 to 2.65%, 85.37 to 64.58% and 376.34 to 352.47kcal/100g respectively. The mineral composition in the samples ranged from 232.05 to 394.62mg/100g for Ca, 76.09 to 122.27mg/100g for Mg, 6.71 to 29.42 mg/100g for Fe, 108.78 to 256.47mg/100g for K, 10.09 to 25.75 mg/100g for Zn. The phytochemical composition of the samples was as follows; 0.067-0.153%, for saponins; 0.043-1.457%, for alkaloids; 1.03-13.77mgGAE/g, for Total phenolics; 3.07-29.31mg/QE, for Total Flavonoids respectively. The composite flour herein produced demonstrates great potential for its use in the development of functional foods given its great nutrients and improved functional characteristics. However sample E with 75%wheat: 20%DPF: 5%OPF surpassed all other samples in terms of the quality attributes and therefore was the best of the formulations.

Inactivation of Soybean Trypsin Inhibitor by Dielectric-Barrier Discharge Plasma and Its Safety Evaluation and Application.

The trypsin inhibitor (TI) is one of the most important anti-nutritive elements in soybeans. As a new nonthermal technology, dielectric-barrier discharge (DBD) cold plasma has attracted increasing attention in food processing. In this research, we investigated the effect of dielectric-barrier discharge (DBD) plasma treatment on soybean trypsin inhibitor content and its structure, evaluated TI toxicity and the safety of its degradation products after treatment with DBD technology in vitro and in vivo, and applied the technology to soybean milk, which was analyzed for quality. Using the statistical analysis of Student's t-test, the results demonstrated that DBD plasma treatment significantly decreased the content of TI (33.8 kV at 1, 3, or 5 min, p &lt; 0.05, p &lt; 0.01, p &lt; 0.001) and destroyed the secondary and tertiary structures of TI. TI was toxic to Caco-2 cells and could inhibit body weight gain, damage liver and kidney functions, and cause moderate or severe lesions in mouse organ tissues, whereas these phenomena were alleviated in mice treated with degradation products of TI after DBD plasma treatment under the optimal condition (33.8 kV at 5 min). The content of TI in DBD-treated soymilk was also significantly reduced (p &lt; 0.001), while the acidity, alkalinity, conductivity, color, and amino acid composition of soymilk were not affected, and there were no statistical differences (p &gt; 0.05). In summary, DBD plasma is a promising non-thermal processing technology used to eliminate TI from soybean products.

Determination and prediction of the available energy and amino acids digestibility of full-fat soybean fed to growing pigs.

Two experiments were conducted to determine the digestible energy and metabolizable energy contents, as well as the apparent ileal digestibility and standardized ileal digestibility of amino acids in full-fat soybean fed to growing pigs. Ten full-fat soybean samples were collected from different areas in China and used in two experiments in this study. In Exp. 1, 66 growing pigs (initial body weight = 18.48 ± 1.2 kg) were randomly allotted to 1 of 11 diets (n = 6) including a corn basal diet and 10 experimental diets formulated by replacing the corn with 30% full-fat soybean. In Exp. 2, 11 growing pigs (initial body weight = 50.45 ± 3.2 kg) were surgically equipped with a T-cannula in the distal ileum and arranged in a 6 × 11 Youden square design with 11 diets and 6 periods. The diets included an N-free diet based on cornstarch and sucrose and 10 experimental diets formulated with full-fat soybeans as the sole source of amino acids. Chromic oxide was added into the diets as an indigestible maker to calculate the digestibility of the amino acids. Results showed that there was considerable variation in neutral detergent fiber, acid detergent fiber, and trypsin inhibitor contents in the 10 full-fat soybean samples with a coefficient of variation greater than 10%. On a dry matter basis, the averaged digestible energy and metabolizable energy values in the 10 full-fat soybean samples were 4,855 and 4,555 kcal/kg, respectively, both were positively correlated with the ether extract content. The best-fitted prediction equations for digestible energy and metabolizable energy of full-fat soybean were: digestible energy, kcal/kg = 3,472 + 94.87 × ether extract - 97.63 × ash (R2 = 0.91); metabolizable energy, kcal/kg = 3,443 + 65.11 × ether extract - 36.84 × trypsin inhibitor (R2 = 0.91). In addition, all full-fat soybean samples showed high apparent ileal digestibility and standardized ileal digestibility values in amino acids and were all within the range of previously published values. Those values significantly varied among different samples (P < 0.05) for most amino acids, except for glycine and proline. In conclusion, full-fat soybean is a high-quality protein ingredient with high ileal digestibility of amino acids when fed to growing pigs, and the metabolizable energy value of full-fat soybean could be predicted based on its ether extract and trypsin inhibitor contents.

Extrusion and product parameters for extruded dog diets with graded levels of whole soybeans

Increasing the fat amount of the ration during extrusion can negatively affect product density and product expansion. Ingredients, like whole soybeans (WSB), which are high in fat may increase energy density while avoiding production issues. The objective of this study was to determine the effect of WSB on extrusion and product characteristics of dry expanded dog food. Experimental diets were extruded with 0, 100, 200, and 300 g/kg, as fed WSB. The processing conditions during extrusion were kept constant across all treatments. Processing outputs, trypsin inhibitor, urease, and phytic acid concentrations were analyzed. Single degree of freedom contrasts were used for statistical analysis and significance at α = 0.05. As WSB increased, the extruder load, die pressure and temperature, and specific mechanical energy (SME) decreased linearly (P < 0.05). The bulk density of the products increased linearly (P < 0.05) while the kibble sectional expansion index (SEI) decreased linearly (P < 0.05) as WSB increased. Post-extrusion, trypsin inhibitor and urease activity decreased, but trypsin inhibitor was not eliminated. In conclusion, the increased inclusion level of WSB changed processing conditions and outputs as a result of the intrinsic and intact fat content. Increasing energy input in processing may destroy anti-nutritional factors completely when WSB are included in diets.

The influence of high pressure processing and germination on anti-nutrients contents, in vitro amino acid release and mineral digestibility of soybeans

To study the effects of germination and high-pressure processing (HPP) on the digestibility of nutrients and anti-nutrient contents. soybeans were treated by germination and HPP for 5 and 10 min at 300, 450 and 600 MPa. The bioaccessibility of minerals (Fe, Zn, Ca), free amino acids (FAA) and starch was determined. The inhibitory activities of phytic acid, tannin and trypsin inhibition activity were studied. The results showed that HPP significantly improved FAA release. The in vitro starch digestibility (IVSD) increased by 2.42 times after germination. Germination and 450 MPa/10 min treatments significantly increased Fe digestibility by 2.07 and 2.06 times, respectively (P < 0.05). Germination and HPP significantly increased Zn digestibility by 2.50 and 1.51 times (P < 0.05), respectively, and HPP increased digestibility of Ca 1.91 times on average. The phytic acid content decreased by 52.4 % and 6.1 % after germination and 300 MPa treatments (P < 0.05), respectively. For tannin, 450 MPa/10 min decreased its content (P < 0.05). The trypsin inhibitor content was reduced by 22.3 % and 10.76 % by germination and 450 MPa/5 min (P < 0.05), respectively. Therefore, the obtained results contribute to enhancing mineral digestibility, releasing FAA, reducing anti-nutrition factors and expanding the utilization of soybeans as food ingredients in the food industry.